It may not have felt it but Sydney has just had one of its warmest March months on record with the city also clearly on the dry side.
The final readings aren't quite done, but Sydney's average maximums are likely to come in at about 26.8 degrees, placing it fourth warmest on record, according to Brett Dutschke, senior meteorologist with Weatherzone. That's two degrees above normal for March.
"It's likely to continue to warmer than average," said Mr Dutschke, noting the on-going influence of El Nino-like conditions in the Pacific Ocean, which tend to mean reduced rainfall across eastern Australia and clearer skies.
Temperatures in the coming week will mostly be above average for the Easter break, with showers expected most days, forecasts show.
Sydney's rainfall for March came in 65.2mm, according to the Bureau of Meteorology's tally, which runs to 9am on the last day of each month. That was about half the city's average for the month, and extends a relatively dry period for Sydney.
The months of February and March were the driest for the period in the past nine years, Mr Dutschke said.
Conditions were much drier in the west of the state. Broken Hill recorded just 5.2 mm for February and March – the driest such period in 24 years for the town – with just 0.4 mm falling for March alone.
Towns such as Balranald and Ivanhoe recorded no rain in their gauges this month.
The only regions of NSW to record more than average rain for the month were in the north-east, such as the Northern Rivers region, Mr Dutschke said.
The bureau is predicting some rainfall relief in coming months, at least for the state's south-western areas.
Warmer-than-usual ocean temperatures in the eastern Indian Ocean favour good rains for central and southern areas of Australia for the coming three months, particularly for April, the bureau said last week.
Conditions also point to above-average temperatures for most coastal areas – including Sydney – especially for overnight temperatures.
El Nino watch
The Bureau of Meteorology, meanwhile, has updated its fortnightly El Nino-Southern Oscillation report, stating that recent warming in the tropics "has primed the Pacific for El Nino".
"International climate models monitored by the Bureau indicate the central tropical Pacific Ocean is likely to continue to warm, with all models predicting El Nino thresholds will be reached or exceeded by mid-year," the agency said, cautioning that models are lower prediction skills at this time of the year.
Still, many of the indicators that signal an emerging El Nino event continue to be observed.
For instance, sea-surface temperature anomalies in the eastern tropical Pacific "have increased by the largest amount for any two-week period since at least July 2001", the bureau said.
Sub-surface waters in the central equatorial Pacific are also continuing to warm, with anomalies exceeding 4 degrees at depths below 100 metres in places. Trade winds, which normally blow east to west, have reversed to become westerlies in parts of the western equatorial Pacific for the past seven weeks.
Apart from raising the odds of a drier and hotter than usual year for most of eastern and southern Australia, an El Nino would also likely boost global temperatures as the Pacific absorbs less heat.
With climate change already lifting the background warmth, an El Nino would increase the chances that 2015 will top 2014 as the hottest year globally on record, climate specialists say.
Weatherzone is owned by Fairfax Media, publisher of this website.
